What matters is how you got it. Accepting a watch someone freely offers you is different from breaking into a house to steal it, even if the watch you were given turns out to be stolen.
For example, if the item was derived from a repository of stolen goods that was already illegal in the US on the basis of it being a repository of stolen goods.
https://arstechnica.com/tech-policy/2024/09/pirate-library-m...